1. Field of the Invention
The present invention relates to a blade guard device, and more particularly to blade guard device for a circular sawing machine.
2. Description of the Related Art
The closest prior art of which the applicant is aware was disclosed in U.S. Pat. No. 5,203,245 to Terpstra, filed on Oct. 19, 1992, entitled "SWINGING BLADE GUARD ASSEMBLY".
However, the blade guard assembly needs to additionally provide a slot 45 which co-operates with a slidable pin 47 for lifting a lower blade guard 25, thereby increasing the parts of the blade guard assembly, and increasing the cost of fabrication. In addition, the stiffness and rigidity of the blade guard assembly are weakened due to provision of the slot 45.
A conventional blade guard device for a circular sawing machine in accordance with the prior art shown in FIG. 1 comprises an upper guard 1, a lower guard 2, a Y-link 3, an elongated bent slot 4, a circular mounting plate 5, and a slide roller 6. In operation, the slide roller 6 is moved with the upper guard 1 to press the Y-link 3 which pulls and rotates the circular mounting plate 5 by the bent slot 4, thereby gradually rotating the lower guard 2 upward so that the circular sawing machine can be adapted to perform a safe sawing process. However, the gradual movement of the lower guard 2 makes the sawing process slow down, thereby greatly effecting the normal sawing operation of the circular sawing machine especially when it is used to saw a thick wood.